Refrigerator



Oct. 8, 1935. w. HIRCHE l 2,016,637

REFRIGERATOR Filed May 2, 1952 2 Sheets-Sheet l W. HIRCHE REFRIGERATORFiled May 2, 1932 2 Sheets-Sheet 2 Patented Oct. 8, 1935 `UNITED STATES2,016,631 nnraicsaa'roa Willy Hirche, Leopoldshain, near zGorlita,Germany, assignor, by mesne assignments, to E.

Rothenberg, Berlin, Germany Application AMay 2, 1932, Serial No. 608,750

In Germany January 2, 1930 16 Claims. (Cl. (i2-115) oil consequentlyfloats on it. An inconvenience connected with refrigerators in whichpure oil is employed for the lubrication of the elements of a gearconsists in that the oil which has to come into touch with the gearelements or the oil which has been carried off by the refrigeratingvapors cannot return into the oil collecting compartment proper withoutspecial auxiliary means, so that the circulation of the oil is'notcontinuous. Several collecting points for the oil are formed in therefrigerator, from which points the oil must be returned by pumps orother suitable auxiliary means to the oil collectingpoint proper. Apartfrom the fact that such a method is complicated, there is no guaranteefor a regular and uniform lubrication. Such refrigerators requirecareful observation which is not compatible with the peculiarlty oftheir purpose of use. Refrigerators must not be delicate and mustrequire little attention. Once such a ma'- chine has been taken intoservice, it must continue to work for a long period without observationthis being only possible if the lubricating oil is automatically,uniformly and continuously circulated through the plant and has noopportunity of collecting in large quantities anywhere except in the oilcollecting chamber proper.

The refrigerator according to the invention lis 30 of such a machinetype which comprises only one main oil collecting compartment, thelubrieating oil returning always automatically to the main collectingpoint after it has fulillled its duty. Care is taken that the quantityof lubri- 40 eating oil which is Vfed to the gearing elements is adaptedto the requirements.

Several embodiments of the invention are illustrated by way of examplein the accompanying drawings in which: 4 Fig. 1 shows diagrammatically aform of construction in section. l

Fig. 2 is a similar view in a modified form of construction.

Fig. 3 is a longitudinal section of a third form 50 of construction.

Fig. 4 is a section on line IV-IV of Fig. 3. In all the forms ofconstruction shown on the drawings a compressor cylinder 2 and a casingI of the driving motor are gas-tightly connected 55 to a crank case I. Acrank shaft l is journaled escape. l a connection-between the motorcasing 3 and the crank case I which is only slightly permeable 2oactions that it no longer ,raf-.issus at Band 6 in the' crank case I anddirectly coupled to the rotor 1 ofthe driving motor. The shaft 4 is notjournaled in the motor casing 3 but carries the motor on its overhangingend.

The result is that oilis prevented from entering 5 the casing 3 which istightly closed for this purpose by a packing 8. The casing- 3 can beremoved from the crank case `I in order'to render the motor accessiblefor repairsv or exchanging. When the casing 3 is removed, the gear box Iis 10 not open to the atmosphere, being still closed by the packing 8.The inner space of the casing 3 is connected to the inner space of thecrank. case I by a tube 9 but this tube is filled with a fine granularsubstance and 'acting like a ili- 16 ter, so that, even when the casing3 is removed, only very small quantities of gases or liquid can Theobject of the tube 9 is. to establish to gas but allows an equalizationof` pressurebetween the casing and the crak case. This lter tube 9 onlybecomes operative when the plant is evacuated in order to removeparticularly all air` and moisture from the motor casing which would 25have a destructive eifect on the motor winding. In the case of suctioneect being exerted for a suiciently long period, all air and moisturewill be removed from the motor casing. It is advisable, when the plantis working, to supply 30 refrigerating medium gas to the air in theinterior of the casing 3 considerably rarified by exhaustion in order toproduce a medium which conducts to the casing the heat developing in themotor winding. This feeding of the refrigerating 4medium gases into thecasing 3 is effected through the filter tube 9. If, in spite of allpacking means, oil should deposit in the motor casing, it can trickleback into the crank case Ithrough thetuber. The oil with 40 therefrigerating medium vapors into the mo- .tor casing mixes with the finemetal particles which have become detached from the parts of the motorsubjected to friction and thus forms a good conductor for the electriccurrent. The 45 polluted oil soon penetrates to the winding of the motorand the metal particles cause a shorting between the windings of thestator winding. If it is desired to prevent this by multiple insulatingof the winding, very cumbersome dirnensions of the stator result and thedanger still exists that at sharp transition points the insulation willbecome so damaged by mechanical works perfectly.- A

covering of the yheads of the winding of the stator with a sheet metalhood certainly protects the winding against the penetration of oil butit prevents evacuating of the air and moisture from the enclosed.lspace, this evacuating being however absolutely necessary in order toprotect the insulation and the winding against destruction and to thusprevent any snorting in the winding. According to the invention theheads I0 of the winding of the stator are covered'with a hood II offilter cloth or some other suitable fabric which prevents the metalparticles mixed with the oil from penetrating to the insulation of thewinding, butl allows the evacuation of air from the winding enclosed bythe hood.

The lower portion of the crank case I merges into an evaporator I2 or isdetachably connected thereto. Cooling ribs I3 project in outwarddirection from the evaporator. At the point of transition between thecrankcase I' and the evaporator I2 a hood I4 is arranged which separatesthe two compartments and has at its centre a rising pipe I5. Theevaporator contains the refrigerating medium liquid, for examplesulphurous acid. An oil collector I6 is provided at the lower portion ofthe crank case I. 'I'he gases forming in the evaporator pass through thehood I4 and the pipe I5 above the oil level in the crank case. The speedof travel of the gases increases in the pipe I5 so that small quantitiesof oil are sucked in by the gases out of the oil compartment throughsmall holes I'I in the wall ofthe pipe l5 and fed to the gear parts. Theoil dripping from these gear parts drops'back directly into the oilcollecting compartment. Any refrigerating `medium .which condenses inthe crank case collects in the lower part of the crank case I as it isheavier than oil and passes through a small aperture I8 at the base ofthe hood back into the evaporator. The gases passing through the pipe I5into the crank case are forced into a'condenserll by a piston 20connected by a piston rod I9 to the crank shaft 4. The gases condense inthe condenser 2| and return in liquid state through a conduit 22 intothe evaporator. The oil particles carried into the condenser returnalong the same path into the evaporator,

where they float on the surface of the liquid re frigerating medium and,when the level of the liquid has suiiciently risen, pass through thehole I8 into the oil collecting compartment.

In the form of construction shown in Fig. 2 the crank case I mergesdirectly into the evaporator so that no partition exists between thetwo.

The oil also oats on the liquid refrigerating medium in the evaporatorand the level of the oil is so high, that the crank 23 when in itsextreme lower position dipsinto `theoil.` Thus, when the refrigerator isworking, the'oil, flung about in the casing by the crank thus reachesall gear parts. Instead of allowing the crank to dip into the oil, it ispossible to bring the oil level close to the crank in its lowermostposition and vto arrange lubricating chains-rings or the like on thecrank shaft which dip into the oil and feed it tothe gear parts. Otherfeeding means may however be provided to bring the oil into contact`with the gear parts. The oil dripping olf drops directly into theoilcollecting compartment. The

parts. -The refrigeratingvmedium, condensingv in the crank case, beingheavier than oil, sinksA through the oil layer and flows back into theevaporator. v

In the form of construction illustrated Figs.

3 and 4 a boiler-like evaporator 24 is connected to the crank case andtubes 26 extend through this evaporator 24. The evaporator 24 has adome-like superstructure 21 which extends alV most the entire length ofthe evaporator. The evaporator wall is open along the length and widthof the dome 2'! so that the gases rising in the evaporator can flowalong the shortest path and collect in the upper portion of the dome. Inorder to facilitate the rising of the gases, the tubes are preferably soarranged that their distance apart in the horizontal directioncontinually increases in the Superposed rows. The upper portion of theevaporator 24 and the lower portion of the dome 2'I form an oilcollecting compartment 28. Between the crank case I and the evaporator24 a partition 29 extends so that the gases are conducted through a pipe30 into the crank case, the other end of the pipe 30 being located inthe gas space of the dome. The pipe 30 is of U-shape and its middleportion extends below the oil layer through the evaporator. To thelowest point of this suction pipe 30 a tube 3| of a lter 32 is connectedlike a nozzle, the pipe 30 being widened at the point of connection 33.25 Th/filter is filled with a fine granular substance 34 which allowsthe oil to only pass through in drops and has in its upper portion,extending into the stored oil, holes 35 for the passage of the oil. Thelter is surrounded by a casing 3B forming an annular space with thefilter 32 which space is also lled with a suitable filtering substance.Lateral holes 3'I in the upper portion of the casing 36 allow oil topass therein.

By choosing a suitable substance for filling the 35 filter the quantityof oil passing therethrough can be adapted to the quantity of oilrequired. The oil drips through the tube 3l into the suction pipe 30 at-its widened portion 33. Owing to the widened cross section of the pipe30 the speed 40 of the gas sucked by the compressor is reduced to suchan extent at this point that the gas can not exert any suction eiect onthe oil. Consequently, the oil drips freely and is only carried off bythe gases when it arrives in the narrower 45 portion of the suctionpipe. Thus, the gas can never carry off more oil than drips from thefilter.

If necessary, the quantity of oil flowing through the filter can beregulated. It is evident, thatA some other suitable throttling elementsmay be 50 fitted instead of the filter illustrated., The oil drippingfrom the gear parts collects in the lower portion of the crank case andpasses into a pipe 38 extending through the bottom of the crank case andterminatinig above the partition 29. This pipe 38 is constructed like asiphon, and its lower end dips into the lubricating oil. When the lowerbend and the rising arm of the pipe 38 is filled with oil the oil passesthrough the upper bend into the downwardly directed arm, the siphon thenbecomes operative and sucks the oil out of the crank case which is thussuddenly emptied. This emptying always takes place automatically atintervals dependent upon the quantity of oil collecting in the crankcase. Consequently, the oil level inthe evaporator is regulatedautomatically and '1s thus maintained at a constant height. Instead ofthe siphon pipe a straight pipe might be employed, the upper end .ofwhich terminates above the partition 29 in 70 *fthe gear box and thelower end of which terminates inthe oil space of the evaporator. Theeffect however would then not be as perfect, as that of the siphon pipe.The oil in this case would only flow in the pipeby gravity, the ow- .inthe oil compartment.

with the lubricating oil,

ing taking place only .when so much oil has collected above the pipethatthe pressure on the oil column is greater than the counter pressurecaused by the pressure in the evaporator and by the vacuumjnthe crankcase.

In the construction illustrated in Figa-3` and 4 the evaporat/r need notbe connected directly to the crank case, as the same effect would takeplace if the two parts are spatially separated and interconnected by thepipes 30 and I8, only the evaporator must be arranged lower than thecrank case. ,The construction according to Figs. 3 and 4 is no/trestricted to the employment of a liquid refrigerating medium which isheavier than lubricati/ng oil, it operates equally advantageously if theliquid refrigerating medium floats on the lubricating oil, only the lter32 must be arranged The especially large oil space in conjunction withthe regulated quantity of lubricating oil fed to the gear parts and theautomatic returning of 'the lubricating oil to the collecting chamberensure a permanently reliable circulation of the oil and a constant-oillevel.

1. A refrigerator in which as refrigerating medium a liquid is employedwhich does not combine comprising in combination a crank case, an oilcollecting chamber below `and communicating with said crank case, anevaporator under said crank case and separated from said crank case bysaid oil chamber, a compressor connected to said crank case, and a pipeextending through said oil chamber having small feed apertures adaptedto accelerate the passage speed of the gases sucked from said evaporatorby said compressor to cause the gases to draw oil through the holes insaid pipe and convey the same into said crank case. 2. A refrigerator inwhich as refrigerating medium a liquid is employed which does notcombine with lubricating oil, comprising in combination a crank case, anevaporator on the lower end of and communicating with said crankcase, acondenser on the upper end of said crank case.

and anejection conduit adapted to convey the tor separating the samefrom said box and having condensed refrigerating medium from said con--denser to said evaporator and terminating in said evaporatorapproximately at the line of transition between the refrigerating mediumand the oil floating thereon. t

3. A refrigeratorin which as refrigerating me dium a liquid is employedwhich does not combine with lubricating oil, comprising in combination acrank case, an oil collecting chamber below and communicating with saidcrank case, an evaporator under said chamber, a hood on said evaporaanaperture near its lower edge for the return of 'condensed refrigeratingmedium from said crank case to said evaporator, and a pipe rising fromsaid hood forming with said hood and the lower portion of said crank anoil collecting chamber.

4. A refrigerator in which as refrigerating medium a liquid is employedwhich doesnot combine with lubricating oil, comprising in combination acrank case, 'a crank shaft journalled'in and projecting from said crankcase an overhanging rotor .mounted on the free -end of said crank shaft,a stator surrounding said rotor, a casing enclosing said'rotor andvcarryingsaid stator detachbly connected to said crank case adapted toand said stator, and a -said evaporator extending to bine withlubricating oil, comprising in combina- 5 tion a crank case, a motorcasing on said crank case, means for preventing the penetration of oilbut allowing a limited penetration of refrigerating medium gases fromsaid crank case into said motor casing. l0

6. A refrigerator in which as refrigerating medium a liquid is employedwhich does not com'- bine with lubricating oil, comprising incombination a crank case, an evaporator under said crank case, a motorcasing on said crank case, a packing between said crank case and saidmotor casing adapted to prevent oil from passing, but to allow therestricted passage of gases from said crank case to said motor casingand, a filter like connection between said motor casing and said 20evaporator adapted to allow a throttled passage of refrigerating medium'gases to pass to said m'otor casing and in conjunction with said packingto allow a circulation of gases tbroughsaid motor casing.

7. A refrigerator in which as-refrigerating medium a liquid is employedwhich does not combine with lubricating oii, comprising in combination acrank case. a motor casing on said crank 4 case, and adjustable meansbetween said crank 30 case and said motor casing adapted to regulate thepassage of gas through said motor casing.

8. A refrigerator in which as refrigerating medium a liquid is employedwhich does not combine with lubricating oil, comprising in combination acrank case, a motor casing on said crank case, a stator winding in saidcasing, a hood of ltercloth on said stator winding adapted to allow theevacuation of air from said winding but preventing the penetration ofmetal particles on to said winding.

9. A refrigerator in which as refrigerating medium a. liquid is employedwhich dqes not comoil oating on but not mixed with the liquidrefrigerating medium in said evaporator extending up to the crank ofsaid crank shaft which crank dips into and distributes the oil to saidcrank parts.

10. A refrigerator in which as refrigerating medium a liquid is employedwhich .does not combine with lubricating oil, comprising in combinationa crank case, an oil chamber below and communicating with said crankcase,;an evaporator below'said oil chamber, a suction pipe between saidcrank case andsaid evaporator extending through said oil chamber adaptedto conduct vthe refrigerating gases from said evaporator to said crankcase, a throttle element iltted in `said suction pipe adapted to supplyby gravity the necessary quantity of oil from said oil chamber o5 tosaid suctiqn pipe to be carried by the gases in said crank case. 11.,.Arefrigerator in which as refrigerating medium a liquid is employed whichdoes not combine with `lubricating oil, comprising in combi- 10 nationagcrank case, an voil chamber below and communicating with said crankcase.- an evaporator under saidv oil chamber, a suction pipe in abovethe level of ou in said ou una mter'- m said ou 76 12. A refrigerator inwhich as refrigerating,

medium a liquid is employed which does not com'- bine with lubricatingoil, comprising in combination a crank case, an oil chamber ybelow andcommunicating with said crank chamber. an evaporator below said oilchamber, a suction pipe in said evaporator extending to above the levelof oil in said oil chamber,rv av illber in said oil chamber, and awidened portion of said pipe connected to said filter tube 'adapted toreduce the flow of gases from said evaporator at the point of -connection with said lter tube to prevent suction elect being exerted onsaid lter tube. 13. A/refrigerator in which as refrigerating medium aliquid is employed which does not combine With lubricating oil,comprising in combination with the crank case, an oil chamber below andcommunicating with said crank case, an evaporator containing said oilchamber, and a pipe connection between said crank case and saidevaporator to conduct the' oil collected in said crank case to said oilchamber, .the upper end of said pipe terminating in said .crank case andits lower end in said oil chamber.

14. A refrigerator in which 'as refrigerating medium a liquid isemployed which does not coin- [A chamber having lateral perforations atits upper bine with iubricatig on,I comprising in combination with thecrank case, an oil chamber below and communicating with said crank case,a silf'phon-like pipe between said crank case and said bine withlubricating oil, comprising in combinax0 tion an oil chamber, anevaporator below said oil chamber of boiler-like constructioncommunicating with said oil chamber by perforations inits upper walldistributed over the entire length and Width of said oil chamber, saidoil chamber being 1D made like a boiler dome and having a space forcollecting the gases rising from said evaporator.

16. A refrigerator in which as refrigerating medium a liquid is employedwhich does not-combine with lubricating oil, comprising in combina- 20tion an oil chamber, an evaporator under said oil chamber of boiler likeconstruction and tubes in said oil chamber for the circulation of therefrigerating medium arranged horizontally in several rows the spacingof the tubes in the diilerent 25 rows widening successively in eachsuperposed row to facilitate the rising of the gas bubbles in saidevaporator.

WILLY HIRCHE.

